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<H1 class="no-header">form_hook 3x 2024-12-28 ncurses 6.5 Library calls</H1>
<PRE>
<STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>                    Library calls                   <STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>




</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
       <STRONG>form_hook</STRONG> - set hooks for automatic invocation by applications


</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
       <STRONG>#include</STRONG> <STRONG>&lt;form.h&gt;</STRONG>

       <STRONG>int</STRONG> <STRONG>set_field_init(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
       <STRONG>Form_Hook</STRONG> <STRONG>field_init(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>

       <STRONG>int</STRONG> <STRONG>set_field_term(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
       <STRONG>Form_Hook</STRONG> <STRONG>field_term(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>

       <STRONG>int</STRONG> <STRONG>set_form_init(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
       <STRONG>Form_Hook</STRONG> <STRONG>form_init(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>

       <STRONG>int</STRONG> <STRONG>set_form_term(FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>,</STRONG> <STRONG>Form_Hook</STRONG> <EM>func</EM><STRONG>);</STRONG>
       <STRONG>Form_Hook</STRONG> <STRONG>form_term(const</STRONG> <STRONG>FORM</STRONG> <STRONG>*</STRONG><EM>form</EM><STRONG>);</STRONG>


</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
       These  functions make it possible to set hook functions to be called at
       various points in the automatic processing  of  input  event  codes  by
       <STRONG>form_driver</STRONG>.


</PRE><H3><a name="h3-set_field_init">set_field_init</a></H3><PRE>
       sets  a  hook to be called at form-post time and each time the selected
       field changes (after the change).


</PRE><H3><a name="h3-field_init">field_init</a></H3><PRE>
       returns the current field init hook, if any (<EM>NULL</EM> if there is  no  such
       hook).


</PRE><H3><a name="h3-set_field_term">set_field_term</a></H3><PRE>
       sets a hook to be called at form-unpost time and each time the selected
       field changes (before the change).


</PRE><H3><a name="h3-field_term">field_term</a></H3><PRE>
       returns the current field term hook, if any (<EM>NULL</EM> if there is  no  such
       hook).


</PRE><H3><a name="h3-set_form_init">set_form_init</a></H3><PRE>
       sets a hook to be called at form-post time and just after a page change
       once it is posted.


</PRE><H3><a name="h3-form_init">form_init</a></H3><PRE>
       returns the current form init hook, if any (<EM>NULL</EM> if there  is  no  such
       hook).


</PRE><H3><a name="h3-set_form_term">set_form_term</a></H3><PRE>
       sets  a  hook  to  be called at form-unpost time and just before a page
       change once it is posted.


</PRE><H3><a name="h3-form_term">form_term</a></H3><PRE>
       returns the current form term hook, if any (<EM>NULL</EM> if there  is  no  such
       hook).


</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
       Routines  that  return  pointers  return <EM>NULL</EM> on error.  Other routines
       return one of the following:

       <STRONG>E_OK</STRONG> The routine succeeded.

       <STRONG>E_SYSTEM_ERROR</STRONG>
            System error occurred (see <STRONG>errno(3)</STRONG>).


</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
       These routines emulate the System  V  forms  library.   They  were  not
       supported on Version 7 or BSD versions.


</PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
       Raymond.


</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="form.3x.html">form(3x)</A></STRONG>



ncurses 6.5                       2024-12-28                     <STRONG><A HREF="form_hook.3x.html">form_hook(3x)</A></STRONG>
</PRE>
<div class="nav">
<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
<ul>
<li><a href="#h3-set_field_init">set_field_init</a></li>
<li><a href="#h3-field_init">field_init</a></li>
<li><a href="#h3-set_field_term">set_field_term</a></li>
<li><a href="#h3-field_term">field_term</a></li>
<li><a href="#h3-set_form_init">set_form_init</a></li>
<li><a href="#h3-form_init">form_init</a></li>
<li><a href="#h3-set_form_term">set_form_term</a></li>
<li><a href="#h3-form_term">form_term</a></li>
</ul>
</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
<li><a href="#h2-AUTHORS">AUTHORS</a></li>
<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
</ul>
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